Abstract: Fluid flow and mixing are major factors affecting reactions，and segregation index is a common parameter for characterizing the mixing degree. Average residence time and residence time distribution are the measure of back-mixing in reactors. In this paper，mixing mechanisms were discussed，and the experimental and mathematical simulation methods for segregation index determination were introduced. The mixing degree could be intensified by external energy or the change in flow patterns and velocities. Four major types of reactors were analyzed and discussed including stirred tank reactor，impinging stream reactor，static mixer and high-gravity rotating bed reactor.

摘要： 流体流动和混合是影响化学反应的重要因素，离集指数是表征流体混合程度的常用参数，平均停留时间及停留时间分布是衡量反应器内流体返混的一个量度。文中分析了反应器内流体的混合机理，介绍了两种实验测定离集指数的方法以及数学模拟法；在微观混合的基础上提出了过程与设备的强化方法，借助外界能量或改变流体流动型态和流速等方法强化流体的混合程度，总结了搅拌釜反应器、撞击流反应器、静态混合反应器、超重力旋转床反应器等设备的混合机理及其优缺点。